Friday, August 29, 2008

These relatively large flies (12-19 mm -- 5/8" or so) don't start showing up around our place until mid-summer. Then, I most often notice Tiger Bee Flies among the rafters on our porch. They often hover near a rafter and then thump it with their heads. I don't quite have the sequence of events worked out yet, but what the flies are doing is hunting for a unprotected nest containing carpenter bee larvae. If successful, the female Tiger Bee Fly will lay her eggs in the nest and her larvae will feed on the carpenter bee larvae.

Monday, August 18, 2008

Another one of the wasp-mimic flies, most thick-headed flies resemble thread-waisted wasps. Adults visit flowers and feed on nectar. Larvae are internal parasites of bumblebees and various wasps. The female Physoconops is said to lay her eggs on host species while in flight. The eggs hatch and bore into the host which they consume from the inside out.

Wednesday, August 13, 2008

Our persimmon tree is loaded with green fruit this year. It's almost as if it know it produced nothing last year due to a late freeze killing all the blooms. The only problem is: Some of the branches are breaking under their load of green persimmons.

Tuesday, August 12, 2008

The common name "Barn Spider" is applied to many different species of spiders in the Family Araneidae (Orb Weavers). Getting a species ID on these spiders from a photo ranges from extremely difficult to totally impossible. Species ID often require a detail examination of the female's genitalia which is well beyond my expertise and inclination.

The spider in the photo above is a female. She is almost twice as large as a male of the same species. She is what I sometimes call a "tidy" spider, meaning that she doesn't leave her web up during the day. Instead, this nocturnal spider rebuilds her web every evening. In the morning, she removes the web by eating it and, thereby, reabsorbing the protein that went into its production. She does leave the primary anchor lines for the web in place. During the day, she stays concealed in a location very near where her web is built.

Above is the under side of the same female spider. The red area at the end of her abdomen (Opisthosoma) are her spinnerets where the web emerges.

Above is a male spider of the same species. Notice the two short appendages emerging from under the spider's "face". There are pedipalps, and are used for sensing the spider's immediate environment, for assisting with eating, and for males, reproduction (specifically sperm deposition). Female spiders also have pedipalps, but if the pedipalps resemble boxing gloves (the tips of the pedipalps are swollen), the spider is an adult male.

Saturday, August 09, 2008

Most folks who are familiar with the name antlion think of the little critters that build funnel-shaped pit traps for catching ants and other small insects. Those are the larvae of a species of antlion closely related to the one above. The adults of those antlions look similar, but are smaller and less colorful.

According to the University of Florida, the larvae of G. gratuslive in dry hollows of trees among fine wood particles, squirrel frass and other fecal matter, and other assorted debris. These hollows are large enough to allow for free movement of the larvae under the surface of the debris and are structured so that rainfall does not fully soak the contents of the hollow. The larvae may dig or run after prey, but not rapidly. At times, larvae may simply lie in wait. They feed on assorted insects found in their microhabitat such as termites, beetle larvae, and ants.

Thursday, August 07, 2008

Like all Velvet Ants this Cow Killer isn't an ant at all. She is a wasp, a flightless, female wasp. (Males have wings and can fly.) Female Cow Killers are in constant motion, scurrying along the ground, presumably searching for bumblebee nests. Once a nest is found, she will dig down into the nest and deposit one egg near the brood chamber. When the egg hatches the larva of the Dasymutilla will enter the bumble bee brood chamber, kill the bee larvae, and feed on them. The Cow Killer larva pupates in the bumble bee brood chamber.

The common name "Cow Killer" is based victim's reports that the sting of the female are painful enough to kill a cow. Like most wasps, the male cannot sting.

Light requirements: Sun (Note: All sources seem to agree that this plant prefers full sun, but ours is growing in thicket at the edge of the yard and receives only a couple of hours of morning sunny. It's in total shade for the remainder of the day.)

Tuesday, August 05, 2008

One of the multitude of leafhoppers -- around 3000 species in North America, 20,000 worldwide -- that feed on plant sap. This particular species is found in the central, northeastern and southeastern USA as well as Mexico.

Many species of leafhoppers coat their bodies and wings with a light dusting of water-repellent waxy material (brochosomes). That's the reason the water is tending to bead up and slide off this Speckled Sharpshooter after a light rain.

Monday, August 04, 2008

This is the caterpillar I've always called a Tomato Hornworm, but it isn't. True, it is usually found munching on tomato plants, but it is actually a Tobacco Hornworm and is the larvae stage of the Carolina Sphinx moth (Manduca sexta). Host plants include all members of the Nightshade Family (Solanaceae) including potatoes, tomatoes and tobacco. In our garden, I haven't found these caterpillars to be all that picky about what they eat. Tomatoes do seem to be their preferred host, but we've also had them strip pepper plants and I often find them on our Datura (Jimpson Weed).

The primary identifying characteristics for the Tobacco Hornworm are the seven diagonal white lines edged with black and the dorsal horn which is orange, pink or red.

There is a Tomato Hornworm. It is the larvae of the Five-spotted Hawk Moth (Manduca quinquemaculata). Tomato Hornworms look very similar, but have eight V-shaped stripes and their dorsal horn is black.

Caterpillar Legs

All caterpillars have three pair of true legs under their thorax, first body segment behind the head. These legs are jointed, segmented and have little hooks on the end. The are usually used for grasping food. Most caterpillars also have five pairs of prolegs under their abdomen. The prolegs are not segmented, but are cylindrical. They are used for walking and clinging, as they have a set of microscopic hooks on the base (crochets). The last pair of prolegs on the anal abdominal segment are usually called claspers. So, most caterpillars are hexadecapodal because they have a total of 16 legs.

There are many non-hexadecapodal caterpillars, notably the inch-worm type cats, which have six true legs, but only 8, 6 or 4 prolegs. There are also caterpillars with no legs at all. And, there are larvae of some wasps and flies that look like caterpillars, but technically are not. They have more than 16 legs.

Sunday, August 03, 2008

Saturday, August 02, 2008

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Background: Due to a variety of circumstances, we did not get our spring garden planted during the spring. Planting occurred in early summer instead, and we are just now starting to harvest some veggies. This is very late for a garden in Arkansas.

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We must cover many crops -- like green beans -- with wire hoops. The cottontail rabbits will destroy them if we don't. The hoops did a great job of keeping the rabbits out, but couldn't keep the bean plants in. Jo prepared for her first picking on Friday by removing all the beans on the outside of the wire. Then, we lifted the hoops off the beans. That worked well. Most of the stems and leaves pulled through the wire just fine.
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Only after the wire hoops were removed did we realize how much the beans were depending upon them for support. The beans sprawled all over the place. (Bucket is unconcerned and waiting for Jo to start picking. Jo shares a few beans with the dogs. Bucket and Rusty eat fresh green beans as if they were dogs treats. In fact, you have to keep an eye on the dogs or they will begin picking their own.)
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Jo picked almost ten pounds of beans. Then, we replaced the wire hoops, tucking the beans back inside as best we could. I hope the bean plants hold up to all the rough handling they received. Under normal circumstances, the next picking should be even larger and then taper off quickly.
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